There is broad scholarly consensus that the relative power of the United States is declining and that this decline will have negative consequences for international politics. This pessimism is justified by the belief that great powers have few options to deal with acute relative decline. Retrenchment is seen as a hazardous policy that demoralizes allies and encourages external predation. Faced with shrinking means, great powers are thought to have few options to stave off decline short of preventive war. Contrary to the conventional wisdom, however, retrenchment is not a relatively rare and ineffective policy instrument. A comparison of eighteen cases of acute relative decline since 1870 demonstrates that great powers frequently engage in retrenchment and that retrenchment is often effective. In addition, we find that prevailing explanations overstate the importance of democracies, bureaucracies, and interest groups in inhibiting retrenchment. In fact, the rate of decline can account for both the extent and form of retrenchment, even over short periods. These arguments have important implications for power transition theories and the rise of China.

How do states use economic-security linkages in international bargaining? Governments can provide economic benefits as a side payment to reinforce security cooperation and use close security ties as a source of bargaining leverage in economic negotiations. Domestic political pressures, however, may constrain the form of linkage. First, economic side payments are more likely to be chosen in areas that will not harm the key interests of the ruling party. Second, involvement by the legislature pushes governments toward using security ties as bargaining leverage for economic gains. Evidence from negotiations between Britain and Japan during the Anglo-Japanese alliance of 1902 to 1923 supports the constraining role of domestic politics. Economic-security linkages occurred as Britain gave favorable economic treatment to Japan in order to strengthen the alliance. Economic competition between the allies, however, made it difficult for Britain to grant asymmetrical economic benefits. In tariff negotiations where business interests had more influence in the domestic policy process, the alliance was used as leverage to force reciprocity.

Why do great powers engage in territorial expansion? Much of the existing literature views expansion as a largely intentional activity directed by the leaders of powerful states. Yet nearly 25 percent of important historical instances of great power expansion are initiated by actors on the periphery of the state or empire without authorization from their superiors at the center. Periphery-driven “inadvertent expansion” is most likely to occur when leaders in the capital have limited control over their agents on the periphery. Through their actions, peripheral agents effectively constrain leaders from withdrawing from these newly captured territories because of sunk costs, domestic political pressure, and national honor. When leaders in the capital expect geopolitical consequences from regional or other great powers, such as economic sanctions, militarized crises, or war, they are far less likely to authorize the territorial claims. A mixed-methods research strategy combines new quantitative data on great power territorial expansion with three qualitative case studies of successful (and failed) inadvertent expansion by Russia, Japan, and France. Inadvertent expansion has not completely gone away, particularly among smaller states, where government authority can be weak, control over states’ apparatuses can be loose, and civil-military relations can be challenging.

Security assistance is a pillar of U.S. foreign policy and a ubiquitous feature of international relations. The record, however, is mixed at best. Security assistance is hard because recipient leaders are often motivated to implement policies that keep their militaries weak. The central challenge of security assistance, then, is influence. How does the United States aim to influence recipient leaders to improve their militaries, and what drives its approach? Influence in security assistance can be understood as an escalation ladder with four rungs: teaching, persuasion, conditionality, and direct command. Washington increasingly delegates security assistance to the Department of Defense, and the latter to the U.S. Army. U.S. Army advisers tend to rely exclusively on teaching and persuasion, even when recipient leaders routinely ignore their advice. The U.S. Army's preference for persuasion and aversion to conditionality in security assistance can be traced to its bureaucratic interests and to the ideology that it has developed—the cult of the persuasive—to advance those interests. A case study examines the bureaucratic drivers of the U.S. Army's persistent reliance on persuasion to influence Iraqi leaders to reform and strengthen the Iraqi Army. Qualitative analysis leverages over one hundred original interviews, as well as oral histories and recently declassified U.S. Central Command documents. The findings illustrate how the interests and ideologies of the military services tasked with implementing U.S. foreign policy can instead undermine it.